A job that used to be done by the mother or grandmother of the new mother or if failing that, by one's own common sense and trial and error.

A lactation consultant is a healthcare provider recognized as an expert in the fields of human lactation and breastfeeding. The USLCA, United States Lactation Consultant Association, is the presiding organization in the United States of America and the International Lactation Consultant Association (ILCA) is the professional association for certified laction consultants internationally. A Board Certified Lactation Consultant will have the initials IBCLC and/or RLC after her/his name, as a physician would have MD or DO, or a registered nurse would have RN. Lactation Consultants can be found in private practice, on staff in hospitals, and in the public health arena._Wikipedia